HUNGARIAN GPS NETWORK TRANSFORMATION INTO DIFFERENT DATUMS AND PROJECTION SYSTEMS

Abstract

The results of the GPS network adjustment are the adjusted co-ordinate components of vectors, the co-ordinates of network stations and accuracy data. We have more options to convert the co-ordinates into national datum depending on whether the co-ordinates of the national initial station are obtained from absolute point positioning (local datum) or the initial station is included in the EUREF network having known co-ordinates. In the latter case a quasi transformation can be performed with the known transformation parameters. To reduce discrepancies we apply 2D Helmert, affine and 5th order polynomial transformations.